1. Field of the Invention
The present invention relates generally to a Cognitive Radio (CR) communication system, and in particular, to a method of renting resources and a system supporting the same for a CR communication system.
2. Description of the Related Art
The rapid development of wireless communication systems and the emergence of various wireless services are a driving force behind the ever-increasing demands for radio resources. However, radio resources are considered as a public asset and are placed under strict government regulations. Due to multiple applications on most of the available frequency bands, it is highly difficult to allocate a frequency band to a new wireless communication system.
CR has been proposed as a solution to this problem. CR senses a licensed but unused frequency band and efficiently shares the frequency band.
CR is based on a point-to-multipoint communications. Hence, a Base Station (BS, hereinafter CR BS) manages radio resources in a CR communication system such that as many Mobile Stations (MSs) as possible can efficiently communicate.
A study reported that wireless communication systems have low frequency utilization in practice. In this context, the CR technology has been introduced to increase frequency utilization and facilitate deployment of a new wireless communication system. The Institute of Electrical and Electronics Engineers (IEEE) 802.22 working group has developed a standard for Wireless Regional Area Network (WRAN) by introducing the CR technology to a Television (TV) frequency band and thus sharing an unused TV band for wireless data communications, seeking to increase frequency utilization and expand wireless Internet service.
CR is a promising technology for managing multiple radio channels and detecting interference, in complementary interworking with future-generation wireless communications. For example, CR enables effective high-speed data transmission without causing frequency interference in a shadowing area existing under a cellular environment or in suburban areas requiring increased cell sizes.
Yet, there are many considerations in applying CR to actual wireless communication systems. Since CR is in the early stages of development, configuration techniques have yet to be specified, and the development of an efficient resource allocation scheme has been problematic.
For CR implementation as described above, there is a need for a method of dynamically renting unused resources from licensed systems without causing interference to radio communications of the licensed systems.